Lodi authorities previously said three other men – Robert Lee, Christopher Costello and Mallory Stewart – had been arrested in connection to the case.

Dr. Shock was killed in the doorway of his Lodi home back on Aug. 1.

Police have not stated a motive.

CBS13 has learned suspect Lee’s now-deceased wife was once a patient of Dr. Shock and that she filed a complaint over treatment she received from him that led to his probation and eventual loss of his license – just months before he was shot and killed.